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<li class="level1"><a href="#properties">属性</a></li>
<li class="level1"><a href="#details">详细信息</a></li>
<li class="level2"><a href="#example-usage">示例用法</a></li>
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<h1 class="title"> QML的SignalTransition类型</h1>
<span class="subtitle"></span>
<!-- $$$SignalTransition-brief -->
<p><a href="qml-qtqml-statemachine-signaltransition.html">SignalTransition</a> 类型提供基于Qt信号的转换。<a href="#details">更多…</a></p>
<!-- @@@SignalTransition -->
<div class="table"><table class="alignedsummary">
<tr><td class="memItemLeft rightAlign topAlign"> 导入语句:</td><td class="memItemRight bottomAlign"> import QtQml.StateMachine 1.12</td></tr><tr><td class="memItemLeft rightAlign topAlign"> Since:</td><td class="memItemRight bottomAlign">  Qt 5.4</td></tr><tr><td class="memItemLeft rightAlign topAlign">继承自：</td><td class="memItemRight bottomAlign"> <p><a href="qml-qtqml-statemachine-qsignaltransition.html">QSignalTransition</a></p>
</td></tr></table></div><ul>
<li><a href="qml-qtqml-statemachine-signaltransition-members.html">所有成员的列表，包括继承的成员</a></li>
</ul>
<a name="properties"></a>
<h2 id="properties">属性</h2>
<ul>
<li class="fn"><b><b><a href="qml-qtqml-statemachine-signaltransition.html#guard-prop">guard</a></b></b> : bool</li>
<li class="fn"><b><b><a href="qml-qtqml-statemachine-signaltransition.html#signal-prop">signal</a></b></b> : signal</li>
</ul>
<!-- $$$SignalTransition-description -->
<a name="details"></a>
<h2 id="details">详细信息</h2>
<p><a href="qml-qtqml-statemachine-signaltransition.html">SignalTransition</a>是 <a href="qmlstatemachine.html">声明状态机框架</a>的一部分。</p>
<a name="example-usage"></a>
<h2 id="example-usage">示例用法</h2>
<pre class="qml">

  import QtQuick 2.0
  import QtQml.StateMachine 1.0 as DSM

  <span class="type"><a href="../qtquick/qml-qtquick-rectangle.html">Rectangle</a></span> {
      <span class="type">DSM</span>.StateMachine {
          <span class="name">id</span>: <span class="name">stateMachine</span>
          <span class="name">initialState</span>: <span class="name">state</span>
          <span class="name">running</span>: <span class="number">true</span>
          <span class="type">DSM</span>.State {
              <span class="name">id</span>: <span class="name">state</span>
              <span class="type">DSM</span>.SignalTransition {
                  <span class="name">targetState</span>: <span class="name">finalState</span>
                  <span class="name">signal</span>: <span class="name">button</span>.<span class="name">clicked</span>
                  <span class="name">guard</span>: <span class="name">guardButton</span>.<span class="name">checked</span>
              }
          }
          <span class="type">DSM</span>.FinalState {
              <span class="name">id</span>: <span class="name">finalState</span>
          }
          <span class="name">onFinished</span>: <span class="name">Qt</span>.<span class="name">quit</span>()
      }
      <span class="type"><a href="../qtquick/qml-qtquick-row.html">Row</a></span> {
          <span class="name">spacing</span>: <span class="number">2</span>
          <span class="type"><a href="../qtquickcontrols/qml-qtquick-controls2-button.html">Button</a></span> {
              <span class="name">id</span>: <span class="name">button</span>
              <span class="name">text</span>: <span class="string">&quot;Finish state&quot;</span>
          }

          <span class="type"><a href="../qtquickcontrols/qml-qtquick-controls2-button.html">Button</a></span> {
              <span class="name">id</span>: <span class="name">guardButton</span>
              <span class="name">checkable</span>: <span class="number">true</span>
              <span class="name">text</span>: <span class="name">checked</span> ? <span class="string">&quot;Press to block the SignalTransition&quot;</span> : <span class="string">&quot;Press to unblock the SignalTransition&quot;</span>
          }
      }
  }

</pre>
<br style="clear: both" /><p><b>参见</b><a href="qml-qtqml-statemachine-statemachine.html">StateMachine</a>、 <a href="qml-qtqml-statemachine-finalstate.html">FinalState</a>和 <a href="qml-qtqml-statemachine-timeouttransition.html">TimeoutTransition</a>。</p>
<!-- @@@SignalTransition -->
<h2>属性文档</h2>
<!-- $$$guard -->
<div class="qmlitem"><div class="qmlproto">
<div class="table"><table class="qmlname">
<tr valign="top" class="odd" id="guard-prop">
<td class="tblQmlPropNode"><p>
<a name="guard-prop"></a><span class="name">guard</span> : <span class="type"><a href="qml-bool.html">bool</a></span></p></td></tr>
</table></div>
</div><div class="qmldoc"><p>保护条件只在计算值为true时启用转换，而在计算值为false时禁用转换，从而影响状态机的行为。</p>
<p>当发出与此信号转换相关联的信号时，将评估保护条件。在保护条件下，信号的参数可以使用如下例所示。</p>
<pre class="qml">

  import QtQuick 2.0
  import QtQml.StateMachine 1.0 as DSM

  <span class="type"><a href="../qtquick/qml-qtquick-rectangle.html">Rectangle</a></span> {
      <span class="type"><a href="../qtquickcontrols/qml-qtquick-controls2-button.html">Button</a></span> {
          <span class="name">anchors</span>.fill: <span class="name">parent</span>
          <span class="name">id</span>: <span class="name">button</span>
          <span class="type">DSM</span>.StateMachine {
              <span class="type">DSM</span>.State {
                  <span class="type">DSM</span>.SignalTransition {
                      <span class="name">targetState</span>: <span class="name">finalState</span>
                      <span class="name">signal</span>: <span class="name">button</span>.<span class="name">mysignal</span>
                      <span class="comment">// the guard condition uses the mystr string argument from mysignal</span>
                      <span class="name">guard</span>: <span class="name">mystr</span> <span class="operator">==</span> <span class="string">&quot;test&quot;</span>
                  }
              }
              <span class="type">DSM</span>.FinalState {
                  <span class="name">id</span>: <span class="name">finalState</span>
              }
          }
          <span class="comment">// define the signal the SignalTransition is connected with</span>
          signal <span class="type">mysignal</span>(string mystr)
          <span class="comment">// on clicking the button emit the signal with a single string argument</span>
          <span class="name">onClicked</span>: <span class="name">button</span>.<span class="name">mysignal</span>(<span class="string">&quot;test&quot;</span>)
      }
  }

</pre>
<p><b>参见</b><a href="qml-qtqml-statemachine-signaltransition.html#signal-prop">信号</a>。</p>
</div></div><!-- @@@guard -->
<br/>
<!-- $$$signal -->
<div class="qmlitem"><div class="qmlproto">
<div class="table"><table class="qmlname">
<tr valign="top" class="odd" id="signal-prop">
<td class="tblQmlPropNode"><p>
<a name="signal-prop"></a><span class="name">signal</span> : <span class="type">signal</span></p></td></tr>
</table></div>
</div><div class="qmldoc"><p>与这个信号转换相关的信号。</p>
<pre class="qml">

  import QtQuick 2.0
  import QtQml.StateMachine 1.0 as DSM

  <span class="type"><a href="../qtquick/qml-qtquick-rectangle.html">Rectangle</a></span> {
      <span class="type"><a href="../qtquickcontrols/qml-qtquick-controls2-button.html">Button</a></span> {
          <span class="name">anchors</span>.fill: <span class="name">parent</span>
          <span class="name">id</span>: <span class="name">button</span>
          <span class="type">DSM</span>.StateMachine {
              <span class="type">DSM</span>.State {
                  <span class="type">DSM</span>.SignalTransition {
                      <span class="name">targetState</span>: <span class="name">finalState</span>
                      <span class="name">signal</span>: <span class="name">button</span>.<span class="name">clicked</span>
                  }
              }
              <span class="type">DSM</span>.FinalState {
                  <span class="name">id</span>: <span class="name">finalState</span>
              }
          }
      }
  }

</pre>
</div></div><!-- @@@signal -->
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